Semiconductor Through-Hole Electrode Etching Process
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Solution Overview
Problem
The conventional manufacturing method of BGA type semiconductor devices with through-hole electrodes requires complex and costly etching processes to expose pad electrodes, leading to insulation failures and reduced yield due to over-etching and electrical connection issues.
Innovation Solution
A method that forms a first insulation film on a semiconductor substrate, creates a via hole exposing the pad electrode, and uses a barrier layer or forms a recess to prevent direct contact between the pad electrode and the substrate, allowing for single-step etching to form a through-hole electrode, reducing manufacturing complexity and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If two times of etching are performed to expose the pad electrode while keeping the insulation film on the side wall, then the pad electrode can be exposed, but the process becomes complex and costly with increased risk of over-etching and insulation failure
Solution Approach 1:
The patent divides the etching process into two distinct stages: first etching through the insulation film to expose the pad electrode, then etching the pad electrode itself to form the through-hole. This segmentation allows each etching step to be optimized independently, reducing the risk of over-etching and simplifying process control compared to attempting to expose the pad while preserving side wall insulation in a single complex etch.
Solution Approach 2:
The patent performs preliminary etching to expose the pad electrode before forming the through-hole. This preliminary action separates the exposure step from the through-hole formation step, allowing better control over etching depth and reducing the complexity of maintaining insulation films on side walls during the entire process.
2Manufacturing precision
If over-etching is performed to ensure pad electrode exposure, then the pad electrode is fully exposed, but insulation failure occurs between the through-hole electrode and semiconductor substrate
Solution Approach 1:
By segmenting the etching process into exposure etching followed by through-hole etching, the patent eliminates the need for excessive etching that would compromise insulation. The first etch step exposes the pad electrode with controlled depth, and the second step forms the through-hole, ensuring insulation is maintained while achieving complete exposure.
Solution Approach 2:
The patent uses the exposed pad electrode as a visual and electrical feedback indicator to determine when the first etching step is complete. Once the pad electrode is visible at the surface, the etching stops, preventing over-etching that would damage insulation layers and cause reliability failures.
3Reliability
If insufficient etching is performed to expose the pad electrode, then insulation is maintained, but electrical connection failure occurs between the pad electrode and through-hole electrode
Solution Approach 1:
The segmented etching process ensures that the first etching step exposes the pad electrode completely, establishing reliable electrical connection potential. The second etching step then creates the through-hole electrode that connects to the exposed pad, ensuring both insulation integrity and electrical connection reliability are achieved through controlled sequential steps.
4Manufacturing precision
If complex etching processes are used to expose pad electrodes, then pad exposure is achieved, but manufacturing cost increases
Solution Approach 1:
While the patent uses multiple etching steps, each step is simpler and more controllable than a single complex etch process. The segmentation allows standard etching equipment and parameters to be used for each step, reducing the need for specialized expensive equipment and complex process control systems, thereby lowering overall manufacturing costs.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach simplifies the etching process, minimizes the risk of insulation failures, and enhances the yield of semiconductor devices by ensuring secure electrical connections with reduced etching control requirements.
Implementation Method 1
a via hole 56, which penetrates through the semiconductor substrate 50 and the second insulation film 55 and exposes the first insulation film 51, is formed by etching the second insulation film 55 and the semiconductor substrate 50
Data Source
AI summary
This invention offers a manufacturing method to reduce a manufacturing cost of a semiconductor device having a through-hole electrode by simplifying a manufacturing process and to enhance yield of the semiconductor device. A first insulation film is formed on a top surface of a semiconductor substrate. A part of the first insulation film is etched to form an opening in which a part of the semiconductor substrate is exposed. Then a pad electrode is formed in the opening and on the first insulation film. A second insulation film is formed on a back surface of the semiconductor substrate. Then a via hole having an aperture larger than the opening is formed. And a third insulation film is formed in the via hole and on the second insulation film. The third insulation film on a bottom of the via hole is etched to expose the pad electrode. After that, a through-hole electrode and a wiring layer are formed in the via hole. Finally, the semiconductor substrate is cut and separated into a plurality of semiconductor dice.